1. Field of the Invention
The invention relates to a control method of spindle motor, and more particularly to a method for starting up the spindle motor in advance.
2. Description of the Related Art
Lately, as the electronic technology advances, optical disks are welcome more and more due to its compact size, high storage capacity and long preserving time for data. Prevalence of the optical disks raises the disk drive to a high demand commodity in the electronic market.
Referring to FIGS. 1 and 2, the disk drive comprises a casing 10 and a tray 11. A spindle motor 16 is disposed in the casing 10. A turntable 14 is disposed on the spindle motor 16 for clamping the disk with a clamper disposed on an upper cover. An optical pickup head 17 is disposed on two guide rods and slidable on the guide rods to read/write data on the disk. When the optical disk is loaded into the disk drive on the tray, it is clamped by the turntable 14 and the clamper. The spindle motor 16 rotates the turntable 14 and the disk so that the optical pickup head 17 is able to read/write data on the disk.
Generally, a firmware is used to judge whether a disk is on the tray 11 and the disk type of the loaded disk. The disk type can be, for example, DVD, CD, rewritable or read only. After the disk type is determined, suitable operating parameters are supplied to the optical pickup head 17 to read/write data on the disk. The firmware supplies a signal to drive/start up the spindle motor after the disk type is determined.
Generally, the spindle motor uses the magnet formed by rare earths materials. The magnet formed by rare earths materials generates stronger magnetic fields than other type magnets such as ferrite or plastic magnets. As a result, the spindle motor using the magnet formed by rare earths materials has a better increasing/decreasing speed performance.
However, production of rare earths materials is reducing and the cost is getting higher. The other type magnets (ferrite or plastic magnets) are also used in the spindle motor of disk drive. Due to the not stronger magnetic fields, the spindle motor using the other type magnets has a lower speed performance than that using the rare earths materials magnet. So the spindle motor using the other type magnets needs longer time to reach the predetermined speed after starting up.